1. Field of the Invention
The present invention relates to a cooling fan for rotating machine, particularly a rotating electric apparatus, and more particularly, to a cooling fan whose structure is improved so that productivity can be improved while high cooling performance is maintained.
2. Related Art
Reduction of size, weight and price of electric machine is in progress. With this trend, an insulation class with a high temperature rise limit is employed as an insulating material to be used, and improvement of cooling capacity in a generator is being promoted. On the other hand, mass production performance and easiness in mounting are also important in mass production of rotating machine.
In order to satisfy these requirements as appropriate, a cooling fan as disclosed in the Patent Document 1 is provided. In this cooling fan, considering molding by a die, notches 1a are provided with an equal interval on the outer circumference side of a main plate 1 and an impeller blade 2b in the axial direction is provided so that fan-shaped plates (side plate) 2a are disposed at positions where the portion of these notches 1a are projected in the axial direction so as to constitute a main plate and a side plate which are not overlapped with each other when seen in the axial direction.
Thus, a cooling fan “F” is formed in which air channels using a centrifugal fan action surrounded by the main plate, the side plate and the impeller blade are arranged intermittently in the circumferential direction.
[Patent Document 1] Japanese Utility Model Laid-Open No. H5-58845
However, in the cooling fan provided by the Patent Document 1, since the air channels as centrifugal fans are arranged only intermittently in the circumferential direction of the fan “F”, its cooling capacity is not necessarily sufficient.
The present invention was made in view of the above points and its object is to provide a cooling fan for rotating machine provided with sufficient cooling performance as well as mass production performance and easiness in mounting.